The common name “daddy long legs” often leads to confusion because it refers to three distinct creatures, not just one. This colloquial term contributes to misunderstandings about whether these animals are spiders and what defines them. Understanding their scientific classification and unique features clarifies this ambiguity.
Understanding the Term “Daddy Long Legs”
The term “daddy long legs” is colloquially applied to three different arthropods: harvestmen, cellar spiders, and crane flies. Each belongs to a separate biological classification, and only one is a true spider.
Harvestmen, belonging to the order Opiliones, are arachnids, but not spiders. Unlike spiders, they have a single, fused body segment, making their cephalothorax and abdomen appear as one oval structure. They lack venom glands and the ability to produce silk for webs.
Cellar spiders, classified under the family Pholcidae, are true spiders. These arachnids possess two distinct body segments: a cephalothorax and an abdomen, often joined by a narrow “waist.” They are known for building loose, irregular webs, commonly found in damp, dark areas like basements and cellars.
Crane flies, belonging to the family Tipulidae, are insects, not arachnids. They have slender bodies, long legs, and wings, giving them a mosquito-like appearance, though much larger. They do not possess fangs or venom.
How to Identify Each Creature
Distinguishing between harvestmen, cellar spiders, and crane flies involves observing physical and behavioral characteristics. Body structures offer immediate clues for identification.
Harvestmen have a visibly fused body, appearing as a single, oval-shaped segment. They typically have two eyes, often located on a raised tubercle in the middle of their body. Harvestmen do not spin webs, and their mouthparts are pincer-like, designed for tearing food rather than injecting venom.
Cellar spiders exhibit two clearly separated body parts, with a noticeable “waist” connecting their cephalothorax and abdomen. These spiders usually have eight eyes, often arranged in specific clusters. They are well-known for constructing messy, tangled webs, and they possess fangs for injecting venom into their prey.
Crane flies are identified as insects by their three distinct body segments: head, thorax, and abdomen, along with six legs and a pair of wings. They typically have compound eyes and do not build webs. Many adult crane flies have reduced mouthparts and cannot bite.
Common Misconceptions Addressed
A common myth claims that “daddy long legs” are among the most venomous spiders but cannot bite humans due to tiny fangs. This urban legend lacks scientific basis.
Harvestmen are not venomous; they lack venom glands. They use pincer-like mouthparts instead of fangs.
Cellar spiders are venomous, but their venom is not considered harmful to humans. Their fangs are capable of piercing human skin, but any bite typically results in only a mild, short-lived sensation.
Crane flies are insects, neither venomous nor capable of biting humans. None of the creatures commonly referred to as “daddy long legs” pose a significant threat to humans.